Display device

ABSTRACT

A display device includes a substrate, a circuit element layer on the substrate, a display element layer on the circuit element layer, a sealing film on the display element layer, an oxide film on the sealing film, a barrier metal layer on the oxide film, and a wiring layer on the barrier metal layer, wherein a surface of the sealing film in contact with the oxide film has concave/convexities, and the barrier metal layer is formed by titanium nitride. A height of the concave/convexities of the surface of the sealing film may be less than 30 nm. A thickness of the oxide film may be 5 nm or less.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority fromthe prior Japanese Patent Application No. 2017-242391, filed on Dec. 19,2017, the entire contents of which are incorporated herein by reference.

FIELD

An embodiment of the present invention relates to a display device.

BACKGROUND

Electronic devices which are operated by touching images such as iconsdisplayed on a screen are becoming prevalent. A display panel used insuch electronic devices is also called a touch panel (or a touchscreen).

A conventional touch panel has a structure in which a touch sensor paneland a display panel overlap. However, a structure in which two panelsoverlapped each other has a problem whereby the thickness of the displaydevice increases. For example, in a display device which is curved orbent called a flexible display, a structure in which a touch sensorpanel and a display panel overlap each other is a cause of impedingflexibility.

Therefore, a structure is known in which the function of a touch sensoris built into a display panel. Since a rib structure or a multi-layerstructure such as a sealing film exists within a display panel, wiringfor use in a touch panel is formed along the surface including a step.However, in this case, there is concern of disconnection or a reductionin connection reliability.

As a technique for preventing a sealing film peeling from a lightemitting element, there is a technique of forming a sealing layer bystacking a first barrier layer having barrier properties againstmoisture and oxygen such as silicon nitride, silicon nitride oxide,silicon oxide, and the like, an base such as amorphous silicon, siliconoxide, and silicon nitride, an intermediate layer covering parts whichlocally protrude on an upper surface of the base, and a second barrierlayer having barrier properties against moisture and oxygen such assilicon nitride and silicon oxynitride (for example, see Japanese LaidOpen Patent Application Publication No. 2014-179278). It is required toprevent defects due to diffusion of moisture and oxygen into theinterior when adopting a structure in which the function of a touchsensor is built into a display panel. In addition, it is required topreventing wiring used for a touch panel from peeling from a sealingfilm. Therefore, there is demand for a technique for improvingdisconnection of the wiring used for the touch panel and connectionreliability.

SUMMARY

A display device according to one embodiment of the present inventionincludes a substrate, a circuit element layer on the substrate, adisplay element layer on the circuit element layer, a sealing film onthe display element layer, an oxide film on the sealing film, a barriermetal layer on the oxide film, and a wiring layer on the barrier metallayer, wherein a surface of the sealing film in contact with the oxidefilm has concave/convexities, and the barrier metal layer includestitanium nitride.

A display device according to one embodiment of the present inventionincludes a pixel part arranged with a plurality of pixels on asubstrate, a terminal part arranged on the outer side of the pixel part,the terminal part including a plurality of terminal electrodes, asealing layer covering the pixel part, a detection electrode overlappingthe pixel part and arranged on the sealing layer, and wiring arranged onthe sealing layer and electrically connected to the detection electrodeand the terminal electrode, wherein the sealing layer includes at leastone inorganic insulation layer, a surface of the inorganic insulationlayer includes a concave/convex structure, and he wiring is arranged incontact with a surface including the concave/convex structure of theinorganic insulation layer.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective diagram showing a structure of a display devicerelated to one embodiment of the present invention;

FIG. 2 is a perspective diagram showing a structure of a pixel region ina display device related to one embodiment of the present invention;

FIG. 3 is a planar diagram showing a structure of a display devicerelated to one embodiment of the present invention;

FIG. 4 is a planar diagram showing a structure of a periphery region ofa display device related to one embodiment of the present invention;

FIG. 5 is a cross-sectional diagram in a line X1-X2 in FIG. 3 showing astructure of a display device related to one embodiment of the presentinvention;

FIG. 6 is a cross-sectional diagram showing a structure of a pixelregion in a display device related to one embodiment of the presentinvention;

FIG. 7 is a flowchart for explaining a manufacturing method of a displaydevice related to one embodiment of the present invention;

FIG. 8A is a cross-sectional diagram showing a manufacturing process ofa display device related to one embodiment of the present invention;

FIG. 8B is a cross-sectional diagram showing a manufacturing process ofa display device related to one embodiment of the present invention;

FIG. 9 is a cross-sectional diagram showing a manufacturing process of adisplay device related to one embodiment of the present invention;

FIG. 10 is a cross-sectional diagram showing a manufacturing process ofa display device related to one embodiment of the present invention;

FIG. 11 is a cross-sectional diagram showing a manufacturing process ofa display device related to one embodiment of the present invention;

FIG. 12 is a cross-sectional diagram showing a manufacturing process ofa display device related to one embodiment of the present invention; and

FIG. 13 is a cross-sectional diagram showing a manufacturing process ofa display device related to one embodiment of the present invention.

DESCRIPTION OF EMBODIMENTS

The embodiments of the present invention are explained below whilereferring to the drawings. However, the present invention can beimplemented in various modes without departing from the gist of theinvention and should not to be interpreted as being limited to thedescription of the embodiments exemplified below. Although the drawingsmay be schematically represented in terms of width, thickness, shape,and the like of each part as compared with their actual mode in order tomake explanation clearer, it is only an example and an interpretation ofthe present invention is not limited. In addition, in the presentspecification and each drawing, the same symbols (or symbols such as a,b attached after a number) are provided to the same elements as thosedescribed with reference to preceding figures and a detailed explanationmay be omitted accordingly. Furthermore, characters denoted by “first”,“second” attached to each element are convenient signs for use indistinguishing each element and unless otherwise stated do not have anyfurther meaning.

In the present specification, when a certain member or region is “above(or below)” another member or region, unless otherwise noted thisincludes not only the case of being directly above “or directly below”another member or region, but also the case of being further above “orfurther below” another member or region, that is, this also includes thecase of above or below another member or region with a separatestructural element included therebetween. Furthermore, in theexplanation below, unless otherwise stated, a side on which a first filmis arranged with respect to a substrate is referred to as “above” or“upper” in a cross-sectional view, and the reverse is explained as“below” or “lower”.

Display Device Structure

FIG. 1 is a perspective diagram showing a display device 100 accordingto one embodiment of the present invention. In the display device 100, apixel part 104 and the touch sensor 108 are arranged on one main surfaceof a substrate 102 which has an insulating surface. A plurality ofpixels 106 are arranged in the pixel part 104. The plurality of pixels106 are arranged in, for example, a row direction and a column directionin the pixel part 104. The touch sensor 108 is arranged to overlap withthe pixel part 104. In other words, the touch sensor 108 is arranged tooverlap the plurality of pixels 106. In the touch sensor 108, aplurality of detection electrodes 107 are arranged in a matrix shape,and are electrically connected to each other in the row direction or thecolumn direction. Furthermore, here the pixel 106 and the touch sensor108 are schematically represented, and their size relationship is notlimited to the description shown in FIG. 1.

The display device 100 includes a first terminal region 112 a which isinput with an image signal and a second terminal region 112 b which isinput with and outputs a signal of the touch sensor 108. The firstterminal region 112 a and the second terminal region 112 b are arrangedat either end part of one main surface of the substrate 102 which has aninsulating surface. The first terminal region 112 a and the secondterminal region 112 b include a plurality of terminal electrodesarranged along the edge of the substrate 102 which has an insulatingsurface. Each of the plurality of terminal electrodes of the firstterminal region 112 a and the second terminal region 112 b iselectrically connected to a flexible printed wiring substrate 114. Adrive circuit 110 outputs an image signal to a pixel 106. The drivecircuit 110 is arranged on one main surface of the substrate 102 or theflexible printed wiring substrate 114.

The substrate 102 which has an insulating surface is formed by memberssuch as glass or plastic (polycarbonate, polyethylene terephthalate,polyimide, polyacrylate) and the like. In the case when the material ofthe substrate 102 is plastic, it is possible to provide flexibility tothe display device 100 by thinning the substrate. That is, a flexibledisplay can be provided by using a plastic substrate as the substrate102.

A polarization plate 116 including a polarizer may be arranged on thepixel part 104 and the touch sensor 108. For example, the polarizationplate 116 is formed from a polarizer which exhibits circularpolarization. The polarization plate 116 is formed by a film basematerial including a polarizer. By arranging the polarization plate 116to overlap the pixel part 104, it is possible to prevent reflection(mirroring) of the display screen. The polarization plate 116 may alsoinclude a color filter layer and a light shielding layer in addition toa polarizer as appropriate.

Furthermore, although omitted in FIG. 1, the pixel 106 includes adisplay element and a circuit element. The touch sensor 108 is preferredto be a capacitance type, and a sensing part is formed by a firstdetection electrode (Tx wiring) and a second detection electrode (Rxwiring) in the touch sensor 108. An interlayer insulating layer isarranged between the pixel part 104 and the touch sensor 108 and isarranged so as not to electrically short circuit each other.

FIG. 2 is a perspective diagram showing a structure of the pixel part104 and the touch sensor 108 arranged above. As is shown in FIG. 2, thepixel part 104 includes a circuit element layer 122 arranged with acircuit element above the substrate 102, and a display element layer 124arranged with a display element. A sealing layer 126 is arranged abovethe display element layer 124. The sealing layer 126 is arranged tocover the surface on the upper side of a pixel region when the observerside main surface is upwards.

The circuit element layer 122 includes an interlayer insulating layer.The interlayer insulating layer insulates wiring arranged in differentlayers. The interlayer insulating layer includes at least one inorganicinterlayer insulating layer and at least one organic interlayerinsulating layer. The inorganic interlayer insulating layer is formedfrom an inorganic insulating material such as silicon oxide, siliconnitride, silicon oxynitride and aluminum oxide or the like. The organicinterlayer insulating layer is formed from an organic insulatingmaterial such as acrylic and polyimide. The circuit element layer 122includes an active element such as a transistor, a passive element suchas a capacitor and a resistor, a wiring connecting these elements, andthese elements are arranged to be buried in the interlayer insulatinglayer.

In the display element layer 124, a light-emitting element or anelectrooptical element which develops an electrooptical effect byapplying a voltage is used as a display element. In the case where anorganic EL element is used as the light emitting element, the displayelement layer 124 is formed including a pair of electrodes distinguishedas an anode and a cathode, an organic layer including an organic ELmaterial, and a partition layer having insulating properties forseparating adjacent organic EL elements. The organic EL element iselectrically connected to a transistor of the circuit element layer 122.

The sealing layer 126 has a structure in which a plurality of insulatingfilms is stacked. FIG. 2 has a structure in which a first inorganicinsulating layer 128, an organic insulating layer 130 and a secondinorganic insulating layer 132 are stacked as the sealing layer 126. Thesealing layer 126 increases the sealing performance by a stackedstructure in which different materials are combined. For example, evenin the case when there are defects in the first inorganic insulatinglayer 128, the organic insulating layer 130 fills the defect parts, andthe second inorganic insulating layer 132 and the third inorganicinsulating layer 190 are further arranged whereby it is possible tocompensate for a deterioration in sealing performance due to thedefects. The first inorganic insulating layer 128, the second inorganicinsulating layer 132 and the third inorganic insulating layer 190 mayalso be arranged to cover the entire surface of the pixel part 104 andat least a part of a region on the outer side the pixel part 104. Thefirst inorganic insulating layer 128 and the second inorganic insulatinglayer 132 may be formed to cover a region further on the outer side ofthe second inorganic insulating layer 132. The outer periphery end partsof the first inorganic insulating layer 128 and the second inorganicinsulating layer 132 do not necessarily have to match.

A first detection electrode 134 and a second detection electrode 140which form a sensing part of the touch sensor 108 are arranged on thesecond inorganic insulating layer 132. A third inorganic insulatinglayer 190 is arranged on an upper layer side of the first detectionelectrode 134 and the second detection electrode 140. Bridge wiring 135is arranged on an upper surface of the third inorganic insulating layer190. Furthermore, although not shown in FIG. 2, the upper surface of thethird inorganic insulating layer 190 and the second detection electrode140 may be covered by an overcoat layer.

The first detection electrode 134 is arranged to extend in a firstdirection and the second detection electrode 140 is arranged to extendin a second direction which intersects the first direction. Although thefirst direction can be an arbitrary direction, it may be, for example, adirection along a column direction corresponding to the arrangement ofthe pixels. In this case, the second direction may be a direction alongthe row direction of the pixels. FIG. 2 shows a structure in which aplurality of rectangular electrodes which form the second detectionelectrode 140 are connected, and shows a structure in which rectangularelectrodes which form the first detection electrode 134 are arrangedapart from each other. The bridge wiring 135 electrically connects twofirst detection electrodes 134 arranged apart from each other via acontact hole arranged in the third inorganic insulating layer 190. Aplurality of first detection electrodes 134 and a plurality of seconddetection electrodes 140 are arranged. In the present embodiment, agroup formed by a plurality of first detection electrodes 134 is alsocalled a first detection electrode pattern, and a group formed by aplurality of second detection electrodes 140 is also called a seconddetection electrode pattern. Furthermore, in FIG. 2, only a part of thefirst detection electrode 134 and a part of the second detectionelectrode 140 are shown, and a plurality of these detection electrodesare arranged aligned across essentially the entire pixel part 104.

Although not shown in detail in FIG. 2, the surface of the thirdinorganic insulating layer 190 has a fine concave/convex structure ofabout several nanometer to several hundred nanometer. Theseconcave/convexities preferably have a height less than 30 nm. Aconcave/convex structure having such a size is formed by etching thesurface of the third inorganic insulating layer 190. For example, in thecase where the third inorganic insulating layer 190 is formed usingsilicon nitride, by performing a dry etching treatment using a gas suchas carbon tetrafluoride (CF₄) or sulfur hexafluoride (SF₆), it ispossible to form a concave/convex structure in the surface of the thirdinorganic insulating layer 190. The etching treatment may be performedto an extent so that the surface of the third inorganic insulating layer190 is slightly etched. For example, by etching the surface of the thirdinorganic insulating layer 190 by about several nanometer to severalhundreds nanometer, a concave/convex structure having substantially thesame size is formed on the surface of the third inorganic insulatinglayer 190. Since the third inorganic insulating layer 190 has this typeof concave/convex structure, it is possible to increase adhesion of thebridge wiring 135.

In the case where the third inorganic insulating layer 190 is formedfrom silicon nitride, an oxide film 191 may be formed on the outermostsurface. The oxide film 191 may have a thickness of 1 nm or more, forexample, the oxide film 191 may have a thickness corresponding to oneatomic layer to several atomic layers. This type of oxide film 191 canbe formed, for example, by a plasma treatment using an oxygen gas or agas containing oxygen oxygen (for example, nitrous oxide (N₂O)) on thesurface of the third inorganic insulating layer 190 which is formed fromsilicon nitride, and oxidizing the surface. Since oxidation by a plasmatreatment can be performed even at low temperatures (200° C. or less),it is possible to perform the treatment without problems even in a statewhere a display element is formed on a lower layer side of the sealinglayer 126. In addition, as another method, a silicon oxide film may bedeposited on the upper surface of the third inorganic insulating layer190 by a plasma CVD method (Plasma Enhanced Chemical Vapor Depositionmethod). It is preferred that the thickness of the deposited oxide film191 is 5 nm or less in an island shape or thin film shape. Since thistype of oxide film 191 is formed on the surface of the third inorganicinsulating layer 190, it is possible to increase adhesion of the bridgewiring 135.

A barrier metal layer 192 may be arranged on a surface of the bridgewiring 135 which contacts the third inorganic insulating layer 190 (orthe oxide film 191). The barrier metal layer 192 is formed by a methodwhich has excellent covering properties such as chemical vapordeposition (CVD) method. A metal nitride or metal oxide havingconductivity is used as the material of the barrier metal layer 192, andtitanium nitride (TiN) is preferably used. The bridge wiring 135includes this type of barrier metal layer 192 and is formed using ametal material such as aluminum (Al), titanium (Ti), tantalum (Ta),molybdenum (Mo) and tungsten (W). By arranging the barrier metal layer192, it is possible to prevent oxygen from diffusing from the oxide film191 to a metal film which forms wiring and prevent defects due to highresistance.

FIG. 3 shows a planar diagram of the display device 100. FIG. 3schematically shows an arrangement of the first detection electrode 134and the second detection electrode 140. For the purposes of explanation,FIG. 3 shows the vertical direction with respect to the surface of thepaper as the Y direction and the horizontal direction as the Xdirection.

In FIG. 3, a plurality of first detection electrodes 134 extend in the Ydirection and a plurality of second detection electrodes 140 extend inthe X direction. Here, one group of the plurality of first detectionelectrodes 134 is set as a first detection electrode pattern 138, andone group of the plurality of second detection electrodes 140 is set asa second detection electrode pattern 144.

Furthermore, the shapes of the first detection electrode 134 and thesecond detection electrode 140 are arbitrary. The first detectionelectrode 134 and the second detection electrode 140 may be arectangular (striped) type or may have a shape which connects diamondtype electrodes as is shown in FIG. 3. By adopting a detection electrodehaving such a rectangular (striped) type or diamond type shape which isarranged continuously, detection sensitivity of the touch sensor 108 canbe improved since good capacitive coupling between the first detectionelectrode 134 and the second detection electrode 140 is formed.

The first detection electrode pattern 138 and the second detectionelectrode pattern 144 are arranged in a region which overlaps the pixelpart 104. In other words, the first detection electrode 134 and thesecond detection electrode 140 are arranged to overlap at least a partof a pixel 106 (a part of a light emitting element arranged in a pixel).By adopting this type of arrangement, it is possible to sense thepresence or absence of a touch using the touch sensor 108 while alsodisplaying an image such as an icon on the pixel part 104.

FIG. 4 is a planar diagram showing a structure of a periphery region ofthe display device 100 according to one embodiment of the presentinvention. FIG. 4 is a partially enlarged diagram of the planar diagramshown in FIG. 3. Referring to FIG. 3 and FIG. 4, the pixel part 104 iscovered by the sealing layer 126 (dotted line indicated by referencenumber 126 shows the position of the end part of the sealing layer inFIG. 3 and FIG. 4). The first detection electrode 134 is electricallyconnected to a first wiring 136 a in an opening part 133 arranged in thesealing layer 126 which is located on the outer side of the pixel part104. The first wiring 136 a is electrically connected to a secondterminal 115 a which is a connection terminal for use in a touch panelarranged in second terminal region 112 b. The second terminal 115 a iselectrically connected to the first terminal 113 a which is electricallyconnected to a flexible printed wiring substrate 114 via a second wiring137 a.

The second detection electrode 140 is electrically connected to thefirst wiring 136 b which is arranged on the outer side of the pixel part104. The first wiring 136 b is electrically connected to the secondterminal 115 b of the second terminal region 112 b. The structures ofthe first wiring 136 b, the first terminal 113 b and the second terminal115 b are the same as the structures of the first wiring 136 a, thefirst terminal 113 a and the second terminal 115 a respectively.

Although not shown in the diagram, in FIG. 3, a plurality of transistorsis arranged in a drive circuit 110 b included in the periphery region118 on the outer side of the pixel part 104. For example, the pluralityof transistors includes an n-channel transistor, a p-channel transistoror both. A drive circuit is formed by this type of a transistor.

A first opening region 120 and a second opening region 121 whichsurround the pixel part 104 respectively are arranged in substrate 102.Although details of the first opening region 120 and the second openingregion 121 are described herein, an organic material is removed betweenthe substrate 102 and the first inorganic insulating layer 128 whichforms the sealing layer 126. In other words, the interlayer insulatinglayer above the substrate 102 includes at least one inorganic interlayerinsulating layer and an organic interlayer insulating layer, andincludes a stacked region in which an inorganic interlayer insulatinglayer and an organic interlayer insulating layer are stacked, and anopening region in which the organic interlayer insulating layer isremoved and the inorganic interlayer insulating layer remains. Thedetails of the first opening region 120 and the second opening region121 are explained using the cross-sectional structure of the pixel part104 described herein. The first wirings 136 a and 136 b are extractedout from the pixel part 104 to the periphery part of the substrate 102passing above the first opening region 120. That is, the first wirings136 a and 136 b are arranged to cross the first opening region 120.

As is shown in FIG. 3, the first opening region 120 and the secondopening region 121 are arranged between the pixel part 104 and thesecond terminal region 112 b. The first opening region 120 and thesecond opening region 121 include opening parts which pass through thesecond insulating layer 168. The first opening region 120 and the secondopening region 121 are arranged along at least one side of the pixelpart 104. It is preferred that the first opening region 120 and thesecond opening region 121 are arranged to surround the pixel part 104.As is shown in FIG. 5, the second insulating layer 168 is separated intoa pixel part 104 side and a drive circuit 110 b side by the firstopening region 120. In other words, the second insulating layer 168which is formed from an organic material is removed at the opening ofthe first opening region 120.

As is shown in FIG. 4, in the display device 100 according to oneembodiment of the present invention, the first opening region 120 andthe second opening region 121 are arranged at a position that crossesbetween the opening part 133 and the second terminals 115 a and 115 b.In the present embodiment, the first wirings 136 a and 136 b areextracted from the pixel part 104 to the periphery part of the substrate102 passing above the first opening region 120 and the second openingregion 121.

As is shown in FIG. 3, the second terminal region 112 b is electricallyconnected to a touch sensor control unit 109 via the flexible printedwiring substrate 114. That is, a detection signal obtained by the firstdetection electrode 134 and the second detection electrode 140 istransmitted to the second terminal region 112 b by the first wirings 136a and 136 b and the second wirings 137 a and 137 b, and then output tothe touch sensor control unit 109 via the flexible printed wiringsubstrate 114.

In the display device 100 according to one embodiment of the presentinvention, the first detection electrode pattern 138 and the seconddetection electrode pattern 144 which form a sensing part of the touchsensor 108 are arranged on the substrate 102. By adopting this type ofstructure, is possible to reduce the thickness of the display device 100since it is not necessary to externally attach a touch sensor which isprovided as a separate part.

FIG. 5 shows a cross-sectional structure of the display device 100according to one embodiment of the present invention. FIG. 5schematically shows a cross-sectional structure of the pixel part 104and the periphery region 118 located on the outer side of the pixel part104. This cross-sectional structure corresponds to the structure alongthe line X1-X2 shown in FIG. 3.

As is shown in FIG. 5, the pixel part 104 and the periphery region 118are arranged on the substrate 102. The periphery region 118 includes awiring part including the first wiring 136 a and a second terminalregion 112 b which includes the first terminal 113 a and the secondterminal 115 a. A first opening region 120 and a second opening region121 formed along the outer periphery of a region where the pixel part104 and the organic insulating layer 130 are respectively formed arearranged in the periphery region 118. The pixel part 104 includes atransistor 146, a light emitting element 150, a first capacitor element152 and a second capacitor element 154. Details of a pixel 106 whichincludes these elements are shown in FIG. 6. Neither the secondinsulating layer 168, a partition wall layer 176 or the organicinsulating layer 130 are arranged on the substrate 102. Moisture easilypasses through since these layers are formed using an organic insulatingmaterial. Therefore, it is possible to block a moisture entrance pathfrom the exterior by arranging the first opening region 120 and thesecond opening region 121 to surround the pixel part 104.

As is shown in FIG. 5, an end part of the organic insulating layer 130which forms the sealing layer 126 is arranged in the first openingregion 120. The first inorganic insulating layer 128, the secondinorganic insulating layer 132 and the third inorganic insulating layer190 extend to the outer side of the end part of the organic insulatinglayer 130. In this way, a structure in which the first inorganicinsulating layer 128 and the second inorganic insulating layer 132contact with each other is formed in the outer side region of theorganic insulating layer 130. In other words, a structure is provided inwhich the organic insulating layer 130 is sandwiched between the firstinorganic insulating layer 128 and the second inorganic insulating layer132, and the end part is not exposed. By adopting this type ofstructure, it is possible to prevent moisture or the like from enteringfrom the end part of the organic insulating layer 130.

A sealing structure is formed by separating the second insulating layer168 formed from an organic insulating material in the periphery region118 by the first opening region 120 and by arranging an inorganicmaterial layer to cover the side surface and the bottom surface of thefirst opening region 120. By sandwiching the second insulating layer 168which is formed of an organic insulating material between inorganicmaterial layers, it is possible to prevent moisture from entering thepixel part 104 from the end part of the substrate 102. It is possiblefor the first opening region 120 which separates the second insulatinglayer 168 to function as a moisture blocking region and this structurecan be called a “moisture blocking structure”.

FIG. 6 shows a cross-sectional structure of a pixel 106 of the displaydevice 100 according to an embodiment of the present invention. Anexplanation of parts which have the same structure as in FIG. 5 may beomitted.

As shown in FIG. 6, the light emitting element 150 is electricallyconnected to the transistor 146. A current flowing between the sourceand the drain of the transistor 146 is controlled by an image signalwhich is applied to the gate, and the light emitting luminosity of thelight emitting element 150 is controlled by this current. The firstcapacitor element 152 holds a gate voltage of the transistor 146 and thesecond capacitor element 154 is arranged in order to prevent a potentialof the pixel electrode 170 from unintentionally fluctuating.Furthermore, the second capacitor element 154 is not an essentialstructure and can be omitted.

As is shown in FIG. 6, a base insulating layer 156 is arranged on thefirst surface of the substrate 102. The transistor 146 is arranged abovethe base insulating layer 156. The transistor 146 includes a structurein which the semiconductor layer 158, the gate insulating layer 160 andthe gate electrode 162 are stacked. The semiconductor layer 158 isformed from an amorphous or polycrystalline silicon or an oxidesemiconductor and the like. A source/drain wiring 164 is arranged on anupper layer of the gate electrode 162 interposed by the first insulatinglayer 166. A second insulating layer 168 is arranged above thesource/drain wiring 164 as a planarization layer.

The first insulating layer 166 and the second insulating layer 168 areinterlayer insulating layers. The first insulating layer 166 is a typeof an inorganic interlayer insulating layer and is formed from aninorganic insulating material such as silicon oxide, silicon nitride,silicon oxynitride or aluminum oxide and the like. The second insulatinglayer 168 is a type of organic interlayer insulating layer and is formedfrom an organic insulating material such as polyimide and acrylic. Aninterlayer insulating layer is formed by stacking in order the firstinsulating layer 166 and the second insulating layer 168 from thesubstrate 102 side. By arranging the second insulating layer 168 whichis formed from an organic insulating material above the first insulatinglayer 166, concave/convexities due to the transistor 146 and the likeare buried and the surface of the first insulating layer 166 isplanarized.

The light emitting element 150 is arranged above on an upper surface ofthe second insulating layer 168. The light emitting element 150 has astructure in which a pixel electrode 170 which is electrically connectedto the transistor 146 and an organic layer 172 and a counter electrode174 are stacked. The light emitting element 150 is a two-terminalelement and light emission of the light emitting element 150 iscontrolled by controlling a value of a current which flows between thepixel electrode 170 and the counter electrode 174. A partition walllayer 176 is arranged above the second insulating layer 168 to cover aperiphery part and to expose an inner side region of the pixel electrode170. The counter electrode 174 is arranged on an upper surface of theorganic layer 172. The organic layer 172 is arranged from a region whichoverlaps the pixel electrode 170 to an upper surface part of thepartition wall layer 176. The partition wall layer 176 is formed from anorganic resin material in order to cover a periphery part of the pixelelectrode 170 and to form a smooth step at the end part of the pixelelectrode 170. Acrylic or polyimide and the like is used as the organicresin material.

The organic layer 172 is formed from a single layer or a plurality oflayers including an organic EL material. The organic layer 172 is formedusing a low molecular weight or high molecular weight organic material.In the case where a low molecular weight organic material is used, theorganic layer 172 may include, in addition to the light emitting layerincluding an organic EL material, a hole injection layer, an electroninjection layer, a hole transport layer and an electron transport layerand the like. For example, the organic layer 172 can have a structure inwhich a light emitting layer is sandwiched between a hole injectionlayer and an electron injection layer. In addition to the hole injectionlayer and the electron injection layer, a hole transport layer, anelectron transport layer, a hole blocking layer and an electron blockinglayer may be appropriately added to the organic layer 172. In addition,although the organic layer 172 is individually formed in each pixelelectrode 170 in FIG. 6, a part or all of the layers which form theorganic layer 172 may be continuously formed across a plurality of pixelelectrodes.

Furthermore, in the present embodiment, the light emitting element 150has a so-called top emission type structure in which light emitted bythe organic layer 172 is radiated to the counter electrode 174 side. Asa result, it is preferred that the pixel electrode 170 has lightreflectivity. In addition to the pixel electrode 170 being formed from alight reflective metallic material such as aluminum (Al) or silver (Ag)and the like, a structure is provided in which a transparent conductivelayer of ITO (Indium Tin Oxide) or IZO (Indium Zinc Oxide) and a lightreflective metal layer are stacked.

The counter electrode 174 is formed from a transparent conductive filmsuch as ITO or IZO which has light translucency and conductivity inorder to allow light emitted from the organic layer 172 to pass through.A layer containing an alkali metal such as lithium or an alkaline earthmetal such as magnesium may be arranged at the interface between thecounter electrode 174 and the organic layer 172 in order to increasecarrier injection properties.

Using the gate insulating layer 160 as a dielectric film, the firstcapacitor element 152 is formed in a region where the semiconductorlayer 158 and the first capacitor electrode 178 overlap. Using a thirdinsulating layer 182 arranged between the pixel electrode 170 and thesecond capacitor electrode 180 as a dielectric film, the secondcapacitor element 154 is formed by the pixel electrode 170 and a secondcapacitor electrode 180 arranged overlapping the pixel electrode. Thethird insulating layer 182 is formed of an inorganic insulating materialsuch as silicon nitride.

A sealing layer 126 is arranged above the light emitting element 150.The sealing layer 126 is arranged to prevent moisture and the like fromentering the light emitting element 150. The sealing layer 126 has astructure in which the first inorganic insulating layer 128, the organicinsulating layer 130 and the second inorganic insulating layer 132 arestacked from the light emitting element 150 side. The first inorganicinsulating layer 128 and the second inorganic insulating layer 132 areformed from an inorganic insulating material such as silicon nitride,silicon oxynitride or aluminum oxide and the like. The first inorganicinsulating layer 128, the second inorganic insulating layer 132 and thethird inorganic insulating layer 190 are formed by coating theseinorganic insulating materials using a sputtering method or a plasma CVDmethod and the like. The first inorganic insulating layer 128, thesecond inorganic insulating layer 132 and the third inorganic insulatinglayer 190 are formed to a thickness of 0.1 μm to 10 μm, preferably 0.5μm to 5 μm. An oxide film 191 may be arranged on the surface of thethird inorganic insulating layer 190.

The organic insulating layer 130 is preferred to be formed from anacrylic resin, polyimide resin or epoxy resin and the like. The organicinsulating layer 130 is arranged at a thickness of 1 μm to 20 μm,preferably 2 μm to 10 μm. The organic insulating layer 130 is formed bya coating method such as spin coating or a vapor deposition method usingan organic material source. It is preferred that the organic insulatinglayer 130 is formed in a predetermined region which includes the pixelpart 104 so as to cover the pixel part 104 and be sandwiched between thefirst inorganic insulating layer 128 and the second inorganic insulatinglayer 132. For example, as shown in FIG. 5, it is preferred that an endpart (outline part) of the organic insulating layer 130 is arrangedbetween the pixel part 104 and the first opening region 120. As aresult, after forming the organic insulating layer 130 on the entiresurface of the substrate 102 by a coating method, it is preferred thatthe outer periphery region is removed by etching, or is formed in apredetermined pattern in advance by a vapor deposition method (maskvapor deposition) using a mask which opens a deposition surface, byinkjet printing, flexographic printing or by gravure printing.Furthermore, as is shown in FIG. 5, an overcoat layer 184 which coversthe wiring part of the pixel part 104 and the periphery region 118 andthe second terminal 115 a and exposes the first terminal 113 a isarranged in an upper layer of the sealing layer 126.

The first detection electrode 134 and the second detection electrode 140may be transparent electrodes which are formed using a transparentconductive film in order to allow light emitted from the light emittingelement 150 to pass through. A film of ITO or IZO which are one type oftransparent conductive film, is formed by a sputtering method.

The first detection electrode 134 and the second detection electrode 140may be formed as a transparent electrode by a printing method using ametal nanowire in addition to an oxide conductive material such as ITOand IZO or may be mesh metal wiring using a metal film. In this case,the mesh metal wiring means a shape obtained by forming a conductivelayer part which forms the first detection electrode 134 and the seconddetection electrode 140 only in a region which does not overlap thelight emitting element 150. For example, at least one of the firstdetection electrode 134 and the second detection electrode 140 may beformed by a mesh wiring having a stacked structure which includes atitanium (Ti) layer, an aluminum (Al) layer and a titanium (Ti) layer.

Preferably, the first detection electrode 134 is formed by a mesh wiringhaving a stacked structure which includes a titanium layer, an aluminumlayer and a titanium layer, and the second detection electrode 140 maybe a diamond electrode formed by a transparent conductive film such asITO or IZO. In this case, the first detection electrode 134 forms anopening part 133 for electrically connecting with the first wirings 136a and 136 b above the second inorganic insulating layer 132, and sincetitanium is located on the outermost surface of the first detectionelectrode 134 in a process of exposing a terminal by removing aninorganic insulating layer above the first terminal region 112 a and thesecond terminal region 112 b, the process likelihood increases.

More preferably, each of the first detection electrode 134 and thesecond detection electrode 140 may be formed by a mesh wiring having astacked structure which includes a titanium layer, an aluminum layer anda titanium layer. Also, in this case, the first detection electrode 134forms an opening part 133 for electrically connecting with the firstwiring 136 a and 136 b above the second inorganic insulating layer 132,and since titanium is located on the outermost surface of the firstdetection electrode 134 in a process of exposing a terminal by removingan inorganic insulating layer above the first terminal region 112 a andthe second terminal region 112 b, the process likelihood increases.Furthermore, even if the wiring for routing from the pixel part 104 tothe periphery region 118 is formed using either the first detectionelectrode 134 or the second detection electrode 140, since it isunnecessary to consider a reduction in film thickness due to etchingunlike the case of forming a routing wiring by a transparent conductivefilm such as ITO or IZO, a thick film is unnecessary and low resistancecan be realized.

FIG. 3 and FIG. 4 show a structure in which a first end part of thefirst wiring 136 a is electrically connected to the first detectionelectrode 134 and a second end part on the opposite side to the firstend part is electrically connected to the second terminal 115 a. Thefirst wiring 136 a is electrically connected to the first detectionelectrode 134 at the opening part 133 arranged in the third inorganicinsulating layer 190. The first wiring 136 a is arranged along an uppersurface of the third inorganic insulating layer 190 from the connectionpart with the first detection electrode 134 to the second terminal 115a. Since the third inorganic insulating layer 190 is arranged along astep formed by the first opening region 120 and the second openingregion 121, the first wiring 136 a is similarly arranged along the step.

As is schematically shown in FIG. 5, in the case when the first wiring136 a is arranged along a step surface, the sticking force (also called“adhesion”) with the third inorganic insulating layer 190 which is abase surface becomes a problem. When adhesion between the first wiring136 a and the third inorganic insulating layer 190 is weak, there is aproblem whereby the first wiring 136 a is peeled off. In order to dealwith such a problem, in the present embodiment, peeling of the firstwiring 136 a is prevented by controlling the surface state of the thirdinorganic insulating layer 190.

FIG. 8A shows a state in which the first wiring 136 a is arranged abovethe sealing layer 126. The sealing layer 126 has a structure in whichthe first inorganic insulating layer 128, the organic insulating layer130, the second inorganic insulating layer 132 and the third inorganicinsulating layer 190 are stacked. The surface of the third inorganicinsulating layer 190 is formed with a fine concave/convex structure ofabout several nanometer to several hundred nanometer by a plasmatreatment (etching). By providing such a concave/convex structure, thethird inorganic insulating layer 190 has a structure in whichwettability is improved and stress is dispersed, thereby adhesion of thefirst wiring 136 a can be increased. Furthermore, FIG. 8A shows astructure in which the first wiring 136 a is stacked with a first wiringlayer 136 a-1, a second wiring layer 136 a_2 and a third wiring layer136 a_3. Among these, the first wiring layer 136 a-1 and the thirdwiring layer 136 a_3 are formed from a high melting point metal such astitanium (Ti), tantalum (Ta) and molybdenum (Mo). The second wiringlayer 136 a_2 is formed from aluminum (Al) or an aluminum alloy and thelike. Even though the first wiring 136 a is provided with such a stackedstructure, since the contact area of the first wiring layer 136 a-1 isincreased due to the fine concave/convexities and stress is dispersed,it is possible to prevent peeling.

FIG. 8B shows a state in which an oxide film 191 is formed on thesurface of the third inorganic insulating layer 190. It is possible toform the oxide film 191 by a plasma treatment using oxygen or a gascontaining oxygen. Alternatively, it is possible to form the oxide film191 by etching the surface of the third inorganic insulating layer 190using an etching gas including oxygen. For example, a mixed gas ofcarbon tetrafluoride (CF₄) and oxygen (O₂) can be used as an etching gascontaining oxygen. In the case where the third inorganic insulatinglayer 190 is formed from silicon nitride, the surface is oxidized by theeffects of oxygen radicals using this type of plasma treatment oretching treatment to form the oxide film 191. The thickness of the oxidefilm 191 may be any thickness as long as it has a thickness of 1 nm orless, for example, the oxide film 191 may have a thickness correspondingto one atomic layer to several atomic layers. Since the oxide film 191forms a hydrophilic surface, it is possible to increase wettability andincrease adhesion of the first wiring 136 a.

FIG. 8B further shows a form in which the barrier metal layer 192 isarranged between the first wiring 136 a and the oxide film 191. Thebarrier metal layer 192 prevents oxygen from dispersing from the oxidefilm 191 to the first wiring 136 a. In this way, it is possible toprevent oxidation of the first wiring 136 a and suppress highresistance. For example, titanium nitride (TiN) or the like can be usedas the barrier metal layer 192. It is also possible to apply the barriermetal layer 192 to the structure shown in FIG. 8A. That is, the sameoperation and effect can be obtained by arranging the barrier metallayer 192 between the concave/convex surface of the third inorganicinsulating layer 190 and the first wiring layer 136 a-1.

According o the present embodiment, it is possible to improve thereliability of wiring by improving adhesion between a sealing layer andthe wiring. Furthermore, although the structure of the third inorganicinsulating layer 190 and the first wiring 136 a is shown in the presentembodiment, the reliability of a touch sensor can be improved byapplying the same structure to the second inorganic insulating layer132, the first detection electrode 134 and the second detectionelectrode 140.

Next, a manufacturing method of the display device 100 is explained.FIG. 7 is a flowchart for explaining manufacturing a method of thedisplay device 100 according to one embodiment of the present invention.FIG. 9 to FIG. 13 are cross-sectional diagrams at each stage of thedisplay device 100 according to one embodiment of the present invention.An explanation is provided below while referring to these diagrams asappropriate.

First, after the circuit element layer 122 and the display element layer124 are formed on one main surface of the substrate 102 which has aninsulating surface, the sealing layer 126 is formed. FIG. 9 shows across-sectional diagram of the display device 100 at this stage.

As is shown in FIG. 9, after the transistor 146, the light emittingelement 150, the first capacitor element 152, the second capacitorelement 154, the second terminal 115, the first opening region 120 andthe second opening region 121 are formed on the substrate 102, the firstinorganic insulating layer 128 is formed to cover these (FIG. 9, FIG. 7(S14)). The first inorganic insulating layer 128 is formed by a vapordeposition method such as a plasma CVD method. The first inorganicinsulating layer 128 is formed using a silicon nitride film or a siliconoxynitride film and the like.

Next, the organic insulating layer 130 is formed by a printing method orthe like (FIG. 7 (S16)). As is shown in FIG. 9, the organic insulatinglayer 130 covers the pixel part 104 and is formed so that it does notprotrude from the first opening region 120. The organic insulating layer130 is formed by an inkjet method or the like. The organic insulatinglayer 130 is formed by ejecting a composition including a precursor of apredetermined organic resin material such as an acrylic resin, apolyimide resin or an epoxy resin from the ink head, and baking thecomposition after applying it onto the pixel part 104. The organicinsulating layer 130 may also be formed using a photosensitive materialusing a development process.

Next, the second inorganic insulating layer 132 is formed (FIG. 7(S18)). As is shown in FIG. 9, the second inorganic insulating layer 132is formed on substantially the entire surface of the substrate 102. Thesecond inorganic insulating layer 132 covers the organic insulatinglayer 130 and is formed in close contact with the first inorganicinsulating layer 128 in a region where the organic insulating layer 130is not arranged.

Since the sealing layer 126 covers the first terminal region 112 a andthe second terminal region 112 b at this stage, a process of patterningthe first inorganic insulating layer 128 and the second inorganicinsulating layer 132 is performed in order to remove the sealing layer126 which covers the first terminal region 112 a and the second terminalregion 112 b (FIG. 7 (S20)).

Next, the first detection electrode 134 and the second detectionelectrode 140 are formed. The first detection electrode 134 and thesecond detection electrode 140 are formed on the sealing layer 126. Inorder to form the first detection electrode 134 and the second detectionelectrode 140, first, a transparent conductive film such as IZO isformed on substantially the entire surface of the second inorganicinsulating layer 132 by a sputtering method (FIG. 10, FIG. 7 (S22)).Following this, the first detection electrode 134 is formed bypatterning into a predetermined shape by a photolithography process asis shown in FIG. 10 (FIG. 7 (S24)). Furthermore, although not shown inFIG. 10, the second detection electrode 140 is also formed at the sametime.

The third inorganic insulating layer 190 is formed on an upper layerside of the first detection electrode 134 (FIG. 11, FIG. 7 (S26)).Similar to the first inorganic insulating layer 128, the third inorganicinsulating layer 190 is formed from a silicon nitride film or a siliconoxynitride film and the like. At this stage, the third inorganicinsulating layer 190 covers the first terminal region 112 a and thesecond terminal region 112 b. A process of patterning the thirdinorganic insulating layer 190 is performed in order to expose the firstterminal region 112 a and the second terminal region 112 b (FIG. 7(S24)). In this patterning process, the opening part 133 which exposesthe first detection electrode 134 is formed.

A fine concave/convex structure is formed on the surface of the thirdinorganic insulating layer 190 (FIG. 7 (S30)). The concave/convexstructure is formed by etching the surface of the third inorganicinsulating layer 190. For example, in the case where the third inorganicinsulating layer 190 is formed from silicon nitride, a dry etchingtreatment is performed using gases such as carbon tetrafluoride (CF₄)and sulfur hexafluoride (SF₆), thereby it is possible to form aconcave/convex structure on the surface of the third inorganicinsulating layer 190. The dry etching process is performed at a lowpower density compared to a usual etching process. This process isperformed by causing fluorine radicals generated by the etching gas toact on the third inorganic insulating layer 190. The concave/convexitieswhich are formed on the surface of the third inorganic insulating layer190 are fine concave/convexities and have a height of about severalnanometer to several hundred nanometer. Preferably, the height is lessthan 30 nm.

The oxide film 191 is formed on the concave/convex surface of the thirdinorganic insulating layer 190 (FIG. 7 (S32)). This process is performedby oxidizing a number of monolayers on the surface of the thirdinorganic insulating layer 190 by a low power plasma treatment such asoxygen ashing. The thickness of the oxide film 191 is preferred to beabout 5 nm in an island shape or thin film shape. Since a fine roughsurface oxide film is formed by performing this type of surfacetreatment on the surface of the third inorganic insulating layer 190, itis possible to improve wettability.

Next, the barrier metal layer 192 is formed (FIG. 12, FIG. 7 (S34)).This step is performed in a process with a high coverage rate such aschemical vapor deposition (CVD). Titanium nitride (TiN) is used as thematerial of the barrier metal layer 192. The barrier metal layer 192prevents defects caused by oxygen dispersing into the wiring from thethird inorganic insulating layer 190.

Next, the first wiring 136 a for electrically connecting the firstdetection electrode 134 and the second terminal 115 a is formed (FIG.13, S32). The first wiring 136 a is formed above the third inorganicinsulating layer 190. The first wiring 136 a is formed above the thirdinorganic insulating layer 190 so as to overcome a step formed by thefirst opening region 120 and the second opening region 121. For example,as is explained in FIG. 8A, the third wiring 136 a is formed with astructure in which an upper and lower part of an aluminum film aresandwiched by titanium films.

Conventionally, in this type of step section, a decrease indisconnection and connection reliability was avoided by increasing thethickness of the wiring. However, in the layer structure in which a dryetching process and the multilayer film process were performed, defectswhich could not be avoided were produced just by increasing thethickness of the wiring cover film at the step section due to theinfluence of a reverse taper structure or a micro-loading effect. Thatis, prevention of wiring cover film formation defects and prevention ofstress distortions were insufficient, and connection reliability wasinsufficient. In addition, increasing the thickness of wiring was linkedto a reduction in light emission resolution of a display area.

However, according to the display device according to the embodiments ofthe present invention described above, by treating the surface of asealing film with a low power plasma such as oxygen ashing, fineroughness of the surface of a sealing film and a surface oxide film areformed which improves wettability. Above this, a barrier metal layer isformed by a process with high coverage properties such as a chemicalvapor deposition method. As a result, even in the case when routingwiring is formed at a section where a step is produced by dry etching orformation of a multilayer film structure, it is possible to dispersestress by increasing adhesion between the routing wiring and the sealingfilm, thereby connection reliability of the routing wiring is improved.In addition, since adhesion between the sealing film and the overcoatlayer 184 is improved, it is possible to improve the generation rate ofdefects such as air bubbles.

In addition, according to the display device according to an embodimentof the present invention, it is possible to simplify the manufacturingprocess while improving wiring reliability by using a titanium nitride(TiN) film as the barrier metal layer. That is, it is possible to formthe titanium nitride film by a reactive sputtering method or a CVDmethod. The titanium nitride film can be dry etched, and can bepatterned in the same process as the first wiring 136 a which is formedusing a titanium film and an aluminum film. Therefore, it is possible tosimplify the manufacturing process.

What is claimed is:
 1. A display device comprising: a substrate having apixel region and a periphery region arranged in an outer side of thepixel region; a circuit element layer on the substrate; a displayelement layer on the circuit element layer; and a sealing film on thedisplay element layer, the sealing film including a first inorganicinsulation layer, a first organic insulation layer on the firstinorganic insulation layer, a second inorganic insulation layer on thefirst organic insulation layer, a third inorganic insulation layer onthe second inorganic insulation layer, and a wiring layer on the thirdinorganic insulation layer, wherein a top surface of the third inorganicinsulation layer has first concave/convexities in the periphery region,the circuit element layer includes a second organic insulation layer,the second organic insulation layer has a first opening, a secondopening and a patterned construction provided between the first openingand the second opening in the peripheral region, the second inorganicinsulation layer, and the third inorganic insulation layer having thefirst concave/convexities are arranged on the second organic insulationlayer, and the second inorganic insulation layer, the third inorganicinsulation layer having the first concave/convexities continuously coverthe first opening, the patterned construction, and the second opening ofthe second organic insulation layer.
 2. The display device according toclaim 1, wherein a height of each of the first concave/convexities ofthe top surface of the third inorganic insulation layer is less than 30nm.
 3. The display device according to claim 1, further comprising adetection electrode overlapping the pixel part; and a wiring arranged onthe third inorganic insulation layer of the sealing layer from the pixelregion to the periphery region and electrically connected to thedetection electrode.
 4. The display device according to claim 3, whereinthe detection electrode is arranged between the second inorganicinsulation layer and the third inorganic insulation layer, the wiring isarranged on the third inorganic insulation layer, and the detectionelectrode and the wiring are electrically connected by a contact holearranged in the third inorganic insulation layer.
 5. The display deviceaccording to claim 3, wherein the wiring includes a first metal layerand a second metal layer provided on the first metal layer, the firstmetal layer is filled in the first concave/convexities of the topsurface of the third inorganic insulation layer.
 6. The display deviceaccording to claim 3, wherein a terminal part in the periphery regionarranged in the outer side of the pixel part, the terminal part includesa plurality of terminal electrodes, the second organic insulating layerhas an opening portion at the terminal part, and the wiring is connectedto one of the terminal electrodes via the opening portion.
 7. Thedisplay device according to claim 1, wherein an oxide film is coatingthe first concave/convexities of the third inorganic insulation layer, abarrier metal layer is arranged on the oxide film.
 8. The display deviceaccording to claim 7, wherein the detection electrode is arrangedbetween the second inorganic insulation layer and the third inorganicinsulation layer, the wiring is arranged on the barrier metal layer, andthe detection electrode and the wiring are electrically connected by acontact hole arranged in the barrier metal layer, the oxide film and thethird inorganic insulation layer.
 9. The display device according toclaim 8, wherein the wiring includes a first metal layer and a secondmetal layer provided on the first metal layer, the first metal layer isdirectly contacted to the barrier metal layer.
 10. The display deviceaccording to claim 9, further comprising a terminal part in theperiphery region arranged in the outer side of the pixel part; whereinthe terminal part including a plurality of terminal electrodes, thesecond organic insulating layer has an opening portion at the terminalpart, and the wiring is connected to one of the terminal electrodes viathe opening portion.
 11. The display device according to claim 7,wherein a thickness of the oxide film is 5 nm or less.